1. Field of Invention
This invention is generally related to artificial root substitutes surgically placed into human jaw bones, and is specifically directed to a locking device for use in a endosseous dental implant suitable for use with both screw type and press-fit prosthetic attachments.
2. Description of Prior Art
Dentists and dental manufacturers commonly supply and use two different types of dental implants: a threaded or screw-type implant, or a press-fit implant, often custom made. Frequently, the type of implant chosen depends on the ability of the implant to maintain its position within the jaw over a period of time. Because the press fit implant typically permits growth of bony tissue within the implant, this type of implant is particularly suitable in instances where there is a potential for improper healing. On the other hand, a threaded implant head is easier to fit and generally more stable over time.
Sometimes jaw bone topography, the shape or size, will not allow for the implant to be positioned in parallel with other abutments. Inherent placement discrepancies later found will often make restoration difficult, if not impossible. A threaded or screw in type of implant is limited by its angle and alignment of the attaching head. Notwithstanding, several types of threaded designs such as floating and indirect screws have been proposed to alleviate the unforeseen alignment problems. These devices are difficult and expensive to install. Moreover, after a prosthetic head is installed, any misalignment of abutments create a higher risk of failure. On the other hand, a custom made press-fit head can be used to precisely meet the paralleling requirements. However, this type of attachment head will typically not work or fit properly in the threaded type implant previously installed. Worse yet, once an implant is integrated within the jaw bone, the edentulous jaw must be rehabilitated if a different type of head is necessitated or preferred.
Therefore, a need exists for a single implant body that can accommodate both a screw-in and press-fit type prosthetic attachments.